Impact of planting green on soil properties under irrigated no‐till soybean

Abstract

AbstractPlanting green refers to the practice of planting a row crop into an actively growing cover crop (CC) and terminating it at or after row crop planting. Planting green could have more beneficial impacts on soil properties, erosion control, nutrient cycling, weed suppression, and other soil ecosystem services because it allows greater CC biomass accumulation than early‐terminated CC. The objectives of this 2‐year study were to evaluate the impact of planting green on soil properties (bulk density, wet aggregate stability, sorptivity, particulate organic matter, organic matter, nutrients, and others) and soybean (Glycine max L.) yield in an irrigated no‐till soybean system in south‐central Nebraska. Treatments were cereal rye (Secale cereale L.) CC terminated 2 weeks before planting (2WBP), CC terminated 2 weeks after planting (2WAP) soybean, and no CC. On average, CC produced 2.35 Mg ha−1 of biomass for 2WBP and 12.03 Mg ha−1 for 2WAP. Both 2WBP and 2WAP reduced N concentration by 48% (31.10 vs. 59.70 mg kg−1) but had no effect on other soil properties compared with no CC. Despite the abundant CC biomass production, terminating 2WAP had little to no effect on most soil properties in the short term (2 years). Wet aggregate stability increased as CC biomass production increased, while soil sorptivity (initial water infiltration) increased as wet aggregate stability increased. CC termination timing had inconsistent effects on soybean yield. In general, after 2 years, planting green had no effect on most soil properties or soybean yield, warranting long‐term studies on this topic.